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Does the CM1000v2 cable modem have a firewall?

KevinC123
Aspirant

Does the CM1000v2 cable modem have a firewall?

When I scan two specific ports from outside my home they show as blocked.

 

nmap -Pn -T4 -p 25,9000 "IP address"

Starting Nmap 6.40 ( http://nmap.org ) at 2022-01-03 16:54 UTC
Nmap scan report for machine.name.com (IP address)
Host is up.
PORT STATE SERVICE
25/tcp filtered smtp
9000/tcp filtered cslistener

Nmap done: 1 IP address (1 host up) scanned in 2.14 seconds

 

I've left out the actual machine name and IP address above, for maybe obvious reasons.

 

I looked through all of the settings on the admin pages via 192.168.100.1 and found nothing that looks to me like firewall or port blocking. Did I miss something? Does the CM1000v2 modem have firewall capability? If so, how can I open the two ports?

 

Thanks much.

Message 1 of 9

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FURRYe38
Guru

Re: Does the CM1000v2 cable modem have a firewall?

CM series modems are modems only. No built in router or firelwall. If you have the CM series modem, you'll need to connect a external wifi router to the modem then configure as needed. Most current router firewall are all automatic with little or no user configurations needed. 

 

If you need a actual firewall applicance device, then you need to connect a firewall device. Do a search as there are many. Sorry, I can't recommend anything. 

My Setup ISP SparkLight | Internet Cable 1000↓/50↑ CM2000 Modem | Wifi Router RBK752(v.5) | Switches NG GS105/8 and XS505M | 

Additional NG HW: C7800/CAX80/CM1100/CM1200/CM2000, Orbi: CBK40, CBK752, RBK50, RBK853, RBK752, RBK953, SXK30 | NightHawk: R7000, R7800, R7960P, R8000, R8500, RAXE500, RAX50, XR450, EX7500/EX7700, GS308v3

View solution in original post

Message 2 of 9

All Replies
FURRYe38
Guru

Re: Does the CM1000v2 cable modem have a firewall?

CM series modems are modems only. No built in router or firelwall. If you have the CM series modem, you'll need to connect a external wifi router to the modem then configure as needed. Most current router firewall are all automatic with little or no user configurations needed. 

 

If you need a actual firewall applicance device, then you need to connect a firewall device. Do a search as there are many. Sorry, I can't recommend anything. 

My Setup ISP SparkLight | Internet Cable 1000↓/50↑ CM2000 Modem | Wifi Router RBK752(v.5) | Switches NG GS105/8 and XS505M | 

Additional NG HW: C7800/CAX80/CM1100/CM1200/CM2000, Orbi: CBK40, CBK752, RBK50, RBK853, RBK752, RBK953, SXK30 | NightHawk: R7000, R7800, R7960P, R8000, R8500, RAXE500, RAX50, XR450, EX7500/EX7700, GS308v3

Message 2 of 9
KevinC123
Aspirant

Re: Does the CM1000v2 cable modem have a firewall?

I suspected that the CM1000v2 modem wasn't blocking traffic. I also have a R6400v2 router, which is connected to the LAN port of the modem. I need to forward two ports to a couple machines, and I know how to do that. It looks like traffic on those ports isn't even reaching the router. My conjecture is that the traffic is blocked by my ISP. They told me I needed to contact Netgear to make sure their products are set up right. I'm pretty sure everything is OK. But, I'm trying to make sure with experts like you.

 

Thanks FURRYe38!

Message 3 of 9
FURRYe38
Guru

Re: Does the CM1000v2 cable modem have a firewall?

Ya, once you have the router set you'll should be good. 

Be sure to save off a back up configuration to file for safe keeping. Saves time if a reset is needed.
https://kb.netgear.com/24231/How-do-I-back-up-the-router-configuration-settings-on-my-Nighthawk-rout...
Enjoy. 📡

My Setup ISP SparkLight | Internet Cable 1000↓/50↑ CM2000 Modem | Wifi Router RBK752(v.5) | Switches NG GS105/8 and XS505M | 

Additional NG HW: C7800/CAX80/CM1100/CM1200/CM2000, Orbi: CBK40, CBK752, RBK50, RBK853, RBK752, RBK953, SXK30 | NightHawk: R7000, R7800, R7960P, R8000, R8500, RAXE500, RAX50, XR450, EX7500/EX7700, GS308v3

Message 4 of 9
KevinC123
Aspirant

Re: Does the CM1000v2 cable modem have a firewall?

Yes, I did save a configuration file for my router, right after I inspected every setting and posted about my router in a separate thread.

Thanks again...

Message 5 of 9
FURRYe38
Guru

Re: Does the CM1000v2 cable modem have a firewall?

Smiley Wink

My Setup ISP SparkLight | Internet Cable 1000↓/50↑ CM2000 Modem | Wifi Router RBK752(v.5) | Switches NG GS105/8 and XS505M | 

Additional NG HW: C7800/CAX80/CM1100/CM1200/CM2000, Orbi: CBK40, CBK752, RBK50, RBK853, RBK752, RBK953, SXK30 | NightHawk: R7000, R7800, R7960P, R8000, R8500, RAXE500, RAX50, XR450, EX7500/EX7700, GS308v3

Message 6 of 9
KevinC123
Aspirant

Re: Does the CM1000v2 cable modem have a firewall?

FURRYe38, would you know why my other post into Home Networking > WiFi Routers > Nighthawk WiFi Routers doesn't show up?

 

It has some of the same information (nmap results) in it as this thread. Its title is similar "Netgear R6400v2 firewall query" in that only the model number changed. Does that kind of similarity trigger this forum to drop the post?

 

Thanks....

Message 7 of 9
FURRYe38
Guru

Re: Does the CM1000v2 cable modem have a firewall?

Possible. Might try "R6400 port foward configuration" as a title and post. 

 

Remove the firewall data also...

My Setup ISP SparkLight | Internet Cable 1000↓/50↑ CM2000 Modem | Wifi Router RBK752(v.5) | Switches NG GS105/8 and XS505M | 

Additional NG HW: C7800/CAX80/CM1100/CM1200/CM2000, Orbi: CBK40, CBK752, RBK50, RBK853, RBK752, RBK953, SXK30 | NightHawk: R7000, R7800, R7960P, R8000, R8500, RAXE500, RAX50, XR450, EX7500/EX7700, GS308v3

Message 8 of 9
FURRYe38
Guru

Re: Does the CM1000v2 cable modem have a firewall?

For your R6400, please post in this forum:

https://community.netgear.com/t5/General-WiFi-Routers-Non/bd-p/home-wifi-routers-general

 

Thank you. 

My Setup ISP SparkLight | Internet Cable 1000↓/50↑ CM2000 Modem | Wifi Router RBK752(v.5) | Switches NG GS105/8 and XS505M | 

Additional NG HW: C7800/CAX80/CM1100/CM1200/CM2000, Orbi: CBK40, CBK752, RBK50, RBK853, RBK752, RBK953, SXK30 | NightHawk: R7000, R7800, R7960P, R8000, R8500, RAXE500, RAX50, XR450, EX7500/EX7700, GS308v3

Message 9 of 9
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